<script>
'use strict'
// console.log(this)
const fn = () => console.log(this)
const fn2 = function() {console.log(this)}
// fn() // window
// fn2()

const obj = {fn, fn2}
// obj.fn() // window
// obj.fn2()

function fn3() {
  //
  return () => console.log(this)
}
const fn4 = fn3()
fn4() // window
const fn5 = fn3.call(obj)
fn5()
</script>